Revert "(hoza) Added PL/SQL book"

This reverts commit abaa7bd125f7583995d35150656de0c42dcfdfe5.
Revert "Revert "(hoza) Added PL/SQL book""

This reverts commit 0748d70ee8b64e29cfce73924c2c6f807de8c547.
Krauklis labs_1,2,4